The Black Hole of Calcutta is a small dungeon in Fort William in Calcutta, India, where troops of Siraj ud-Daulah, the Nawab of Bengal, holds British prisoners of war after the Bengali army captures the fort on June 20, 1756.

John Zephaniah Holwell, one of the British prisoners and an employee of the East India Company, said that, after the fall of Fort William, the surviving British soldiers, Anglo-Indian soldiers, and Indian civilians were imprisoned overnight in conditions so cramped that many people died from suffocation and heat exhaustion, and that one hundred and twenty-three of one hundred and forty-six prisoners of war died.